From: Mike Marciniszyn <mike.marciniszyn@intel.com>
Date: Tue, 15 May 2018 18:31:24 -0700
Subject: IB/{rdmavt,hfi1}: Change hrtimer add to use pinned version
Patch-mainline: v4.18-rc1
Git-commit: 3ce459cd684b7f18ca79838e62310ffdc930920b
References: bsc#1096793 FATE#325050
Given we are dealing with nano-second level timers, when the timer
pops, ensure it happens on the CPU which caused the timer to be set
in the first place. This avoids excessive jitter from the desired
expiration time by avoiding the cost of switching our context to
another CPU that is cache cold for this given timer.
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/hw/hfi1/rc.c | 2 +-
drivers/infiniband/sw/rdmavt/qp.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/infiniband/hw/hfi1/rc.c
+++ b/drivers/infiniband/hw/hfi1/rc.c
@@ -2016,7 +2016,7 @@ void process_becn(struct hfi1_pportdata
unsigned long nsec = 1024 * ccti_timer;
hrtimer_start(&cca_timer->hrtimer, ns_to_ktime(nsec),
- HRTIMER_MODE_REL);
+ HRTIMER_MODE_REL_PINNED);
}
spin_unlock_irqrestore(&ppd->cca_timer_lock, flags);
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -2078,7 +2078,7 @@ void rvt_add_rnr_timer(struct rvt_qp *qp
to = rvt_aeth_to_usec(aeth);
trace_rvt_rnrnak_add(qp, to);
hrtimer_start(&qp->s_rnr_timer,
- ns_to_ktime(1000 * to), HRTIMER_MODE_REL);
+ ns_to_ktime(1000 * to), HRTIMER_MODE_REL_PINNED);
}
EXPORT_SYMBOL(rvt_add_rnr_timer);